Trussed brake-lever.



F. SCHAEFER.

TRUSSED BRAKE LEVER. APPLICATION FILED DEC. 7. 1914.

Patented Dec. 14, 1915.

FIG-l F16 la WITNESSES yVM 76 W FREDERIC SCHAEFER, O1 PITTSBURGH, PENNSYLVANIA.

TRUSSED BRAKE-LEVER.

Specification. of Letters Patent.

Patented Dec. 1 1, 1915..

Application filed. December 7, 1914. Serial No. 875,840.

To all whom it may concern:

Be it known that T, Fniionnro Sormnnnn, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Trussed Brake-Levers, of which the following is a specification.

This invention relates to wrought metal brake levers and method of making the same.

The object of the invention is to provide a trussed brake lever formed of wrought metal, of light weight, strong construction and convenient and economical to manufacture.

The invention comprises a trussed wrought metal brake lever and method of forming the same as hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a plan view of a blank plate or bar after it is slit and preparatory to spreading; 1 is a similar view of a portion of a slightly modified blank or bar; Fig. 2 is a transverse section on the line 2-2, Fig. 1; Fig. 3 illustrates the blank or bar after it is spread; Fig. 1- is a plan view of the blank forming the fulcrum member of the lever; Fig. 5 is a plan view of the completed lever; Fig. 6 is an end view of the same; Fig. 7 is a transverse section on the line 77, Fig. 5; and Fig. 8 is a similar view on the line 8S, Fig. 5.

The improved brake lever is formed of wrought metal, preferably from ordinary rolled plate or bar metal. If formed from a plate it is cut to suitable length and width to form the brake lever, while if formed from bar metal, the bar can be rolled to the proper width and thickness, and need only be cut to length. Figs. 1 and 1 show such blanks with their ends preferably rounded, as at 1.1 or 11*, and slit preparatory to spreading. These blanks are slit for the greater portions of their lengths, as shown at 13. The slit can be made in any suitable way. Fig. 1 shows a slit such as would be formed by a saw or like tool, while Fig. 1 shows a slit such as is formed by a punching cutter, which does not remove any of the metal, but has the effect of slightly spreading the blank, thus leaving the end portions 12 slightly narrower than the body.

The next step consists in spreading apart the longitudinal members or limbs 14-, 15 to substantially the form shown in Fig. 3,

forming an open truss, with the space between the limbs of elongated diamond shape, one end of which may be more acute than the other.

Fig. 4: shows the blank 16 for forming the strut or fulcrum member of the trussed lever. This is a short section of plate or bar metal, preferably of the same thickness as the body of the lever, and being of such length and having its end portions formed as shown at 17 so that it fits snuglybetween the limbs 1-1, 15 at their point of greatest spread. This strut member is placed between the limbs 14 and 15, and is then welded at its ends to said limbs, at the points indicated by the dotted lines 18, Fig. 5. This welding operation can be performed in any suitable wav, either by local heating by means of an electric are or the oXi-acetylene process, or by heating the parts in a gas or coal fire, and then pressing between dies so arranged as to force the contacting portions of the limbs and strut member tightly together.

To finish the lever it is merely necessary to punch the strut member with the fulcrum hole 19 and the ends of the lever with the holes 20. These holes if desired could be punched before the slitting operation, but it is preferred to punch them after the slitting operation so as to secure greater accuracy in the relative spacing of the respective holes.

If desired, the body of the lever can be formed in two similar longitudinal portions, each. portion comprising a limb 1a or 15, and having the ends of said portions welded together as indicated by the dotted lines 21, Fig. 5. When formed in this manner each longitudinal member is preferably bent to the desired shape, so that when the end portions are welded together a blank of the form shown in Fig. 3 is produced. It is preferred, however, to form the body portion from a single integral plate or bar, as shown in Fig. 8, by splitting the blank and spreading it apart.

This brake lever is so designed that the line of stress in each of its limbs or truss members lies at the neutral axis of the limb, the lines converging at the points of application of the load. These lines of stress are indicated by the lines 22 and 23 respectively, and it will be observed that they are at the neutral axes of the limbs, and that they converge at the center of the holes 20, at which point the loads are applied. As a conse quence the compression and tension in each limb is balanced, and a heavy load can be safely'applied to a lever of light weight.

The brake lever described can be formed of a good quality of wrought steel, either rolled or forged, preferably ordinary rolled plate or bar steel, and therefore possessing maximum tensile strength. By shaping it into the form of a trussa relatively light lever can be-made of suflicient strength to take care of very heavy strains. The method of manufacture is simple, requiring no complicated or special machinery or diflicult mechanical operations, so that the lever can be fabricated at a low cost.

What I claim is l. A trussed wrought metal brake lever having a body formed of two longitudinal vmembers or limbs united at their ends and spread apartequally intermediate their ends, and a strut member welded between the 1ongitudinal members or limbs at the point of their greatest spread and leaving one symmetrical opening along the center line of the lever on either side of said strut.

2. A trussed Wrought metal brake lever having a body formed of two longitudinal members or limbs having the same cross sec- Copies of this patent may be obtained for five cents each,

tion united at their ends and spread apart equally intermediate their ends, and a strut member welded between the ends of the longitudinal members or limbs at the point of their greatest spread, said strut member and the ends of the lever being provided with holes, and said lever being symmetrical about a longitudinal axis through said holes.

3. A trussed wrought metal brake lever having a body provided with end holes and formed of two longitudinal members or limbs having the same cross section united at their ends and spread apart equally intermediate their ends, and a strut member welded between the longitudinal members or limbs at the point of their greatest spread and leaving triangular openings between said members symmetrical along the longitudinal axis of the lever, the lines of stress in said longitudinal members or limbs lying at the neutral axes thereof and the centers of said holes.

In testimony whereof, I have hereunto set my hand.

FREDERIO SCHAEFER.

Witnesses:

'VVILLIAM B. VHARTON, GLENN H. Lnmsscrrn.

by addressing the Commissioner of Patents.

Washington, D. 0.

meeting at 5 

